In a wireless communication in a millimeter wave band, a MIMO (Multiple Input Multiple Output) beam forming technique is used. For example, protocol specifications of the millimeter wave band using a MIMO beam forming technique are specified in IEEE (The Institute of Electrical and Electronics Engineers, Inc) 802. 11ad.
Conventionally, there is disclosed an adaptive beam forming system using a hierarchical weight bank for an antenna array in a wireless communication system (see, for example, Japanese National Publication of International Patent Application No. 2007-529955).
In wireless communication using a MIMO beam forming technique, for performing high-quality wireless communication, it is important to fast select an accurate beam pattern.